In an empty theatre, a woman is watching an American film - "Ma's Sin" - which tells the weird revenge story of a middle-aged wife, driven mad by jealousy and a deep feer of dying. During the screening, the viewer's fantasies embodied in male characters harass her. Thus she will live the double adventure of the projected motion picture and of her own mental film. But as the lights turn on, she leaves the theatre, apparently unaffected.